The present invention relates to wheel servicing machines, and more particularly to tire changing machines with one or more angularly moveable swing arms for assisting in wheel servicing operations.
In some conventional wheel servicing tasks, an operator places a wheel rim on a rotatable wheel holder which is mounted on the base of the machine. The operator secures the rim to the wheel holder and then mounts a tire onto the wheel rim using a mount/demount head or other tool to force the bead of the tire over the wheel rim. The mount/demount head is typically attached to a swing arm that can be moved in and out of position relative to the wheel rim so that a tool on the swing arm may engage the tire to mount or demount the tire on the wheel rim.
Conventional wheels rims and tires are available in numerous sizes. This requires that a swing arm be moveable in order to accommodate different sizes of various tires and wheel rims. Additionally, an operator may choose to use a tool positioned on a swing arm for some, but not all, wheel servicing operations. Thus, the swing arm should be moveable away from the wheel rim when not being used.
In some applications, if the swing arm is not held in place, it has the potential to swing outwardly, injuring either the operator or another person nearby. For example, during some wheel servicing operations, force may be applied suddenly against the swing arm which could dislodge the swing arm or cause the swing arm to move rapidly away from a desired position.
To combat this problem operators are typically required to hold the swing arm in place manually, which limits the use of an operator's hand. Moreover, manual securement of the swing arm does not guarantee the swing arm will remain at the desired location. Others have attempted to solve this problem by providing an angular stop for the swing arm. However, conventional solutions only restrict movement of the swing arm in one angular direction, and do not prevent the swing arm from moving freely in the opposite angular direction. Thus, previous efforts are insufficient because they still allow the swing arm to rotate outwardly. The swing arm would also be able to move outwardly during the operation of the tire changing apparatus into an undesirable position unless the operator continually holds the swing arm into position manually.
What is needed then are improvements in wheel servicing machines and more particularly in latching devices and associated methods for selectively securing a swing arm at a desired angular location on a tire changing machine.